Work
We build a small number of things and try to get them right.
First product · iOS
Moneyfactor
An auto-financing calculator that shows you what a dealer's numbers actually mean.
Car leases are quoted in a unit almost nobody outside the industry understands: the money factor. It looks like a rounding error — 0.00125 — but multiply it by 2,400 and you get the APR. Dealers are allowed to mark it up over the lender's buy rate, and that markup is one of the least visible ways a lease gets more expensive.
Moneyfactor does the arithmetic dealers do, on your phone, before you sign. It calculates lease and loan payments, compares leasing against buying, works backward from a quoted monthly payment to the money factor implied by it, and flags when that rate looks marked up.
What it does
- Lease and loan calculators — payments, capitalized cost, residual value, taxes, fees, and drive-off totals
- Money factor detector — compares a quoted rate against typical buy rates and shows the likely markup
- Lease vs. buy — the same vehicle costed both ways, side by side
- Reverse-solve — derive the money factor hidden inside a quoted monthly payment
- Lease-end buyout — estimate whether buying out a lease beats returning it
- Saved scenarios and PDF export — keep deals to compare, or take the full breakdown into the dealership
How it's built
Swift and SwiftUI, targeting current iOS. Every calculation runs on the device — the app has no servers, makes no network requests, and collects no data. It has no account system and asks for no permissions. The math is covered by an automated test suite, and lease results have been checked against independent industry calculators.
Where it's honest
Reference rates are estimates, and the app labels them that way rather than implying certainty it doesn't have. Money factor buy rates vary by lender, region, credit tier, and month; Moneyfactor shows a confidence level alongside each reference value and explains where the number came from. It's a tool for walking into a negotiation informed — not a substitute for the lender's actual terms.